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OAS - Osservatorio Astronomico Sormano |
| OAS > SAEL - Small Asteroids Encounters List ( Priority List of Asteroids with H > 22.0 or up to 240 mt in diameter) |
|
OAS - Osservatorio Astronomico Sormano |
| OAS > SAEL - Small Asteroids Encounters List ( Priority List of Asteroids with H > 22.0 or up to 240 mt in diameter) |
Last update: May 25, 2013
Computations by: Piero Sicoli , Francesco Manca (sormano@tin.it).
This list includes small asteroids ( H > 22 or up to 240 mt in diameter) having an Earth MOID (Minimum Orbital Intersection Distance) distance lower than 0.015 AU, and is a complement of the ( MBPL )Minor Body Priority List for objects of smaller size. Circumstances of the encounters with our planet are closer in time to the epoch of available observations and are reported in italic and within <angle brackets>. Moreover closest approaches for three centuries are computed only for objects having orbital elements with the uncertainty number U lower or equal to 5. For information about the U parameter adopted by the Minor Planet Center see MPC 24597 and the related page about the U value.
For the most interesting close encounters (depending on MOID, U parameter, nominal distance, propagation of the error etc.) the future minimum (min) and maximum (max) miss distances in AU are computed using the OrbFit Software Package ( F. Manca). These values, based on a 3-sigma uncertainty confidence level, are reported at the left of the nominal result and a symbol " r " means that available radar observations have been included in the orbital solution.
For all the entries, Earth MOID (software by F. Manca , G. Matarazzo , P. Sicoli , Sormano Observatory , see internal report N.50, 1996 ) and encounter parameters (software by A. Testa , Sormano Observatory) are computed again at each orbit update.
Any comment and/or suggestion will be welcomed.
For related information, see also:
Ephemeris Service:
Close Encounters and Selected Objects lists:
Virtual Impactor:
obs@cfa.harvard.edu.
The following service, courtesy of the Minor Planet
Center, is intended as support and in addition to the objects available in the SAEL list for which follow-up or recovery is needed.
The service will return all objects (NEOs and Comets) based on criteria specified by the user and
NOT filtered in relation to their MOID value.
Astrometric observations of any of the following objects should be sent directly
to obs@cfa.harvard.edu.